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The Cartography & Visualization section encapsulates competencies related to the design and use of maps and mapping technology. This section covers core topics of reference and thematic maps design, as well as the emerging topics of interaction design, web map design, and mobile map design. This section also covers historical and contemporary influences on cartography and evolving data and critical considerations for map design and use.

Topics in this Knowledge Area are listed thematically below. Existing topics are in regular font and linked directly to their original entries (published in 2006; these contain only Learning Objectives). Entries that have been updated and expanded are in bold. Forthcoming, future topics are italicized.

Maps communicate information about the world by using symbols to represent specific ideas or concepts. The relationship between a map symbol and the information that symbol represents must be clear and easily interpreted. The symbol design process requires first an understanding of the underlying nature of the data to be mapped (e.g., its spatial dimensions and level of measurement), then the selection of symbols that suggest those data attributes. Cartographers developed the visual variable system, a graphic vocabulary, to express these relationships on maps. Map readers respond to the visual variable system in predictable ways, enabling mapmakers to design map symbols for most types of information with a high degree of reliability.

Terrain representation is the manner by which elevation data are visualized. Data are typically stored as 2.5D grid representations, including digital elevation models (DEMs) in raster format and triangulated irregular networks (TINs). These models facilitate terrain representations such as contours, shaded relief, spot heights, and hypsometric tints, as well as automate calculations of surface derivatives such as slope, aspect, and curvature. 3D effects have viewing directions perpendicular (plan), parallel (profile), or panoramic (oblique view) to the elevation’s vertical datum plane. Recent research has focused on automating, stylizing, and enhancing terrain representations. From the user’s perspective, representations of elevation are measurable or provide a 3D visual effect, with much overlap between the two. The ones a user can measure or derive include contours, hypsometric tinting, slope, aspect, and curvature. Other representations focus on 3D effect and may include aesthetic considerations, such as hachures, relief shading, physiographic maps, block diagrams, rock drawings, and scree patterns. Relief shading creates the 3D effect using the surface normal and illumination vectors with the Lambertian assumption. Non-plan profile or panoramic views are often enhanced by vertical exaggeration. Cartographers combine techniques to mimic or create mapping styles, such as the Swiss-style.

The selection of appropriate type on maps, far from an arbitrary design decision, is an integral part of establishing the content and tone of the map. Typefaces have personalities, which contribute to the rhetorical message of the map. It is important to understand how to assess typefaces for their personalities, but also to understand which typefaces may be more or less legible in a labeling context. Beyond the choice of typeface, effective map labels will have a visual hierarchy and allow the user to easily associate labels to their features and feature types. The cartographer must understand and modify typographic visual variables to support both the hierarchy and label-feature associations.

In this entry, we introduce tenets of usability engineering (UE) and user-centered design (UCD), interrelated approaches to ensuring that a map or visualization works for the target use. After a general introduction to these concepts and processes, we then discuss treatment of UE and UCD in research on cartography and geographic visualization. Finally, we present a classification of UE evaluation methods, including a general overview of each category of method and their application to cartographic user research.

Advances in personal computing and information technologies have fundamentally transformed how maps are produced and consumed, as many maps today are highly interactive and delivered online or through mobile devices. Accordingly, we need to consider interaction as a fundamental complement to representation in cartography and visualization. UI (user interface) / UX (user experience) describes a set of concepts, guidelines, and workflows for critically thinking about the design and use of an interactive product, map or otherwise. This entry introduces core concepts from UI/UX design important to cartography and visualization, focusing on issues related to visual design. First, a fundamental distinction is made between the use of an interface as a tool and the broader experience of an interaction, a distinction that separates UI design and UX design. Norman’s stages of interaction framework then is summarized as a guiding model for understanding the user experience with interactive maps, noting how different UX design solutions can be applied to breakdowns at different stages of the interaction. Finally, three dimensions of UI design are described: the fundamental interaction operators that form the basic building blocks of an interface, interface styles that implement these operator primitives, and recommendations for visual design of an interface.

Describe the baseline expectations that a particular map makes of its audience

Compare and contrast the interpretive dangers (e.g., ecological fallacy, Modifiable Areal Unit Problem) that are inherent to different types of maps or visualizations and their underlying geographic data

Identify several uses for which a particular map is or is not effective

Identify the particular design choices that make a map more or less effective

Evaluate the effectiveness of a map for its audience and purpose

Design a testing protocol to evaluate the usability of a simple graphical user interface

Perform a rigorous sampled field check of the accuracy of a map

Discuss the use limitations of the USGS map accuracy standards for a range of projects demanding different levels of precision (e.g., driving directions vs. excavation planning)

Discuss the extent, classification, and currency of government data sources and their influence on mapping

List the data required to compile a map that conveys a specified message

Discuss the issue of conflation of data from different sources or for different uses as it relates to mapping

Describe a situation in which it would be acceptable to use smaller-scale data sources for compilation to compile a larger scale map

Describe the copyright issues involved in various cartographic source materials

Explain how data acquired from primary sources, such as satellite imagery and GPS, differ from data compiled from maps, such as DLGs

Explain how digital data compiled from map sources influences how subsidiary maps are compiled and used

Explain how geographic names databases (i.e., gazetteer) are used for mapping

Explain how the inherent properties of digital data, such as Digital Elevation Models, influence how maps can be compiled from them

Identify the types of attributes that will be required to map a particular distribution for selected geographic features

Determine the standard scale of compilation of government data sources

Assess the data quality of a source dataset for appropriateness for a given mapping task, including an evaluation of the data resolution, extent, currency or date of compilation, and level of generalization in the attribute classification

Discuss the nature and use of virtual environments, such as Google Earth

Explain how various data formats and software and hardware environments support immersive visualization

Compare and contrast the relative advantages of different immersive display systems used for cartographic visualization (e.g., CAVEs, GeoWalls)

Evaluate the extent to which a GeoWall or CAVE does or does not enhance understanding of spatial data

Explain how the virtual and immersive environments become increasingly more complex as we move from the relatively non-immersive VRML desktop environment to a stereoscopic display (e.g., a GeoWall) to a more fully immersive CAVE

Discuss the differences between maps that use the same data but are for different purposes and intended audiences

Discuss Tufte’s influence (or lack thereof) on cartographic design

Critique the graphic design of several maps in terms of balance, legibility, clarity, visual contrast, figure-ground organization, and hierarchal organization

Critique the layout of several maps, taking into account the map audience and purpose and the graphic design (visual balance, hierarchy, figure-ground), as well as the map components (north arrow, scale bar, and legend)

Design maps that are appropriate for users with vision limitations

Apply one or more Gestalt principles to achieve appropriate figure-ground for map elements

Prepare different map layouts using the same map components (main map area, inset maps, titles, legends, scale bars, north arrows, grids, and graticule) to produce maps with very distinctive purposes

Prepare different maps using the same data for different purposes and intended audiences (e.g., expert and novice hikers)

Describe differences in design needed for a map that is to be viewed on the Internet versus as a 5-by 7-foot poster, including a discussion of the effect of viewing distance, lighting, and media type

As internet use has grown, many paper maps have been scanned and published online, and new maps have increasingly been designed for viewing in a web browser or mobile app. Web maps may be static or dynamic, and dynamic maps may either be animated or interactive. Tiled web maps are interactive maps that use tiled images to allow for fast data loading and smooth interaction, while vector web maps support rendering a wide variety of map designs on the client. Web maps follow a client-server architecture, with specialized map servers sometimes used to publish data and maps as geospatial web services. Web maps are composed of data from a database or file on the server, style information rendered on either server or client, and optionally animation or interaction instructions executed on the client. Several graphic web platforms provide user-friendly web mapping solutions, while greater customization is possible through the user of commercial or open source web mapping APIs. When designing web maps, cartographers should consider the map’s purpose on a continuum from exploratory and highly interactive to thematic and less interactive or static, the constraints of desktop and/or mobile web contexts, and accessibility for disabled, elderly, and poorly connected users.